Struct ControlSet 

pub struct ControlSet {
    pub name: String,
    pub binding: String,
    /* private fields */
}

Polydat write node: submit an f64 write against the named control via the session root’s walk-up. Returns 1 if dispatched, 0 if not — either no session root is installed (outside a running scenario / pure-kernel test) or the control already reads exactly the requested value (idempotent writes are elided; see the fixpoint check in the body).

Signature: control_set(name: const str, value: f64) -> u64. Authored via #[polydat::polydat_node] (SRD-80b).

Writes are non-blocking — the node spawns a tokio task that calls nmbrs_metrics::controls::ErasedControl::set_f64 and does not await it (awaiting would deadlock the single-threaded runtime). The control layer’s confirmed-apply still runs in the background; failures log but do not stall the issuing fiber. SRD 23 §“Mutation entry points → GK-driven feedback loops”.

Purity is SideChannel(Other): the write is an observable side effect on runtime control state, so the node is never const-folded or deduped — it dispatches on every evaluation.

Fields

name: String

The name argument, as given at construction.

binding: String

The binding value, computed once at construction.

Implementations

impl ControlSet

pub fn new(ctx: &BuildContext, name: String) -> Self

A control_set node with the given constant arguments.

Trait Implementations

impl PolydatNode for ControlSet

fn meta(&self) -> &NodeMeta

Return this node’s metadata (port names and types).

fn eval(&self, inputs: &[Value], outputs: &mut [Value])

Evaluate the node: read from inputs, write to outputs.

fn compiled_slot( &self, wire_types: &[PortType], _engine: Engine, ) -> Option<CompiledSlotKit>

Return a slot-compiled closure for nodes with typed-slice ports (§8.4 layer 3): slice inputs read (ptr, len) slot pairs; vector outputs write into kernel-owned scratch. Checked by the compiled-kernel builders AFTER Self::compiled_u64 — pure-scalar nodes never need it. Default None: the node stays on typed eval.

fn purity(&self) -> Purity

Declare this node’s purity status per the runtime_model.md’s D2 axiom. Default: Purity::Pure. Override to declare an observable side channel (Purity::SideChannel) or eval-call-spanning state (Purity::Nondeterministic).

fn scratch_layout(&self) -> Vec<ScratchElem>

The scratch entries a state owns for this node’s evaluation (axiom S3), one per entry in the order the node expects them in Self::eval_in. Empty for a node that evaluates over Values alone, which is every node but a native cone.

fn eval_in( &self, scratch: &mut [ScratchBuf], inputs: &[Value], outputs: &mut [Value], )

Self::eval with the node’s scratch, which the evaluating state owns and hands in: storage belongs to the state, never to the node, which is shared by every state of the program.

fn commutativity(&self) -> Commutativity

Declare which inputs are interchangeable for this node.

fn accepts_none_inputs(&self) -> bool

True iff this node should receive Value::None inputs directly rather than have the kernel propagate None through it. Default: false — most nodes follow none_semantics.md Rule 1 (None in → None out, no eval invocation).

fn compiled_u64(&self) -> Option<Box<dyn Fn(&[u64], &mut [u64]) + Send + Sync>>

Return a compiled u64-only evaluation closure, if this node operates entirely in u64 space.

fn jit_constants(&self) -> Vec<u64>

Return assembly-time constants for JIT compilation.

fn simd_variant(&self) -> Option<SimdVariant>

Explicit SIMD-native implementation of this scalar node, if one has been registered with a semantic contract.

fn fusion_subgraph(&self) -> Option<FusionSubgraph<'_>>

A synthetic fusion node’s view of the subgraph it stands in for (cone extraction, engines.md §2). Program-identity hashing (PolydatProgram::canonical_hash) walks THROUGH fusion nodes into this subgraph, so identity is invariant to the engine mix: jit=off and jit=auto compiles of the same source hash identically, and resume-skip matching survives mode changes. Default None: ordinary nodes hash as themselves.